Microsoft SQL for Beginners

Use the where clause to filter rows by column values, applying operators like greater than, less than, equal to, and not equal, with practical examples.

Use where clause to filter rows with equals and not equals, filter birthdates with greater than or equal to and less than, and note case-insensitive matching on the HumanResources.vEmployee view.

Master building complex where clauses with and and or operators, and learn how parentheses affect evaluation order in SQL queries. Explore predicate logic and truth tables to verify results.

Explore how SQL evaluates boolean expressions in where clauses by using parentheses to control and/or precedence, with examples using ListPrice, Color, and StandardCost.

Master the in and between operators and like wildcards to filter data in HumanResources.vEmployee and Sales.vStoreWithDemographics, using percent and underscore for flexible name and sales range queries.

Master the where clause in SQL with wildcards, brackets, and ranges to filter data, and learn is null versus is not null for null values, using and or.

Master how to order results with ORDER BY using column names, ordinals, or aliases, choose ASC or DESC, and note aliases work there but not in where.

Learn to order results with the order by clause using last name, column ordinals, and aliases in ascending or descending order, and sort ties with multiple columns, with where clauses.

Apply inner joins as intersections of tables to return columns in a single query. Use table aliases and join on product subcategory IDs to show product name and subcategory name.

Expand your understanding of inner joins by matching production.product with production.productSubcategory to reveal subcategory names and linking to production.productCategory for category names.

Left and right outer joins are essentially the same, differing only by order, and the product–subcategory example shows how left outer join returns all left rows with nulls for nonmatches.

Learn to use left outer joins and inner joins to combine sales order data with salesperson, employee, and territory names, showing totals even when a salesperson is missing.

Learn to build a complete sql statement using from, inner and left outer joins, where, and order by, filtering the northwest territory and ordering by total due with table aliases.

Explore aggregate functions—max, min, count, count distinct, avg, and sum—that return a scalar value, and apply them with group by and having using real examples from Sales.SalesOrderHeader and Person.Person.

Explore SQL aggregate functions, including standard deviation and variance, and sum with a 2006 order date filter. Learn to avoid summing non-numeric values and prep for group by and having.

Group by clause groups values to answer questions like sales by salesperson or stock by product. Use aggregate functions with group by, ensuring all selected columns are grouped or aggregated.

Group by multiple columns to compute total sales by territory and salesperson for 2006, then replace ids with names via joins and optionally show full names.

Explore how the having clause filters groups by aggregate functions, unlike the where clause, with examples like sum(total due) greater than 4 million and subcategories with at least 15 products.

Learn how the having clause filters groups by aggregates, using department employee counts and sales totals to illustrate grouping, count, sum, and conditional operators like between and in.